Hi Jason, On 3/19/24 20:02, Jason Gunthorpe wrote:
On Tue, Mar 12, 2024 at 01:14:20PM -0500, Shivaprasad G Bhat wrote:The commit 090bad39b237a ("powerpc/powernv: Add indirect levels to it_userspace") which implemented the tce indirect levels support for PowerNV ended up removing the single level support which existed by default(generic tce_iommu_userspace_view_alloc/free() calls). On pSeries the TCEs are single level, and the allocation of userspace view is lost with the removal of generic code.:( :( If this has been broken since 2018 and nobody cared till now can we please go in a direction of moving this code to the new iommu APIs instead of doubling down on more of this old stuff that apparently almost nobody cares about ??
We have existing software stack deployments using VFIO userspace device assignment running on Power platform. We have to enable similar software stack on newer generation Power10 platform and also in a pSeries lpar environment. These distros rely on VFIO enabled in kernel and currently have IOMMUFD disabled. This patch series is a simpler low risk enablement that functionally get the software stack working while we continue to enable and move to IOMMUFD in phases. We have to fix the older APIs in order to stage the functional enablement in small increments. We are working on iommufd support for pSeries and looking forward to Timothy's patches. -Thanks Shivaprasad
Jason
